Ovulation is your window of opportunity for conception. It's the once-monthly release of an egg from your ovary, and the best time to try and make a baby. The tricky part is that ovulation can vary from month to month (even in the same woman), making it hard to predict. Try our ovulation calculator, or use this mathematical equation (don't worry, no algebra!) to put yourself in the ballpark.
Subtract 14 to 16 days from the date you expect your next period to start to find your likely time of ovulation. Your mission: Start having sex five or six days prior, every other day. (If your cycle is longer than 35 days or shorter than 21 days, or if the your cycle significantly varies from month to month, this equation might be off). Or, to avoid the math, buy an ovulation predictor kit at the drugstore. Pee on a stick around the time you expect to ovulate, and the color will let you know when it's time.
Cervical mucus gives another clue to ovulation. (Yeah, it's gross, but it pales in comparison to all the bodily fluids you'll come to know during pregnancy and birth!) Reach your fingers up there, and pull out some mucus. If it can stretch about three inches between your fingers without breaking, ovulation is imminent.